초록 ▼

A process for concentrating and recovering methane and carbon dioxide from landfill gas includes absorption of commonly occurring pollutants using a reduced amount of carbon dioxide absorbent which itself may be an in situ derived and recoverable constituent. Separated methane may be concentrated in

A process for concentrating and recovering methane and carbon dioxide from landfill gas includes absorption of commonly occurring pollutants using a reduced amount of carbon dioxide absorbent which itself may be an in situ derived and recoverable constituent. Separated methane may be concentrated into a high heating value fuel, and a highly pure food-grade carbon dioxide product may also be recovered. Process streams may be used to provide fuel for compression and refrigeration and/or to regenerate carbon dioxide absorbent.

대표청구항 ▼

[ What is claimed is:] [1.] A gas separation process for separating carbon dioxide, methane and trace contaminants contained in a landfill gas feed stream comprising the steps of:separating said trace contaminants from said landfill gas feed stream to form a methane product gas stream containing sub

[ What is claimed is:] [1.] A gas separation process for separating carbon dioxide, methane and trace contaminants contained in a landfill gas feed stream comprising the steps of:separating said trace contaminants from said landfill gas feed stream to form a methane product gas stream containing substantially only carbon dioxide, methane and nitrogen,introducing said methane product gas stream into an absorption column for contact with a solvent to form a second methane product containing substantially only methane and nitrogen and a carbon-dioxide enriched bottom product containing substantially only solvent and carbon dioxide,separating said second methane product by liquefaction into a gaseous overhead liquefaction product comprising a methane and nitrogen mixture and a liquid liquefaction product comprising methane,introducing said carbon dioxide-enriched bottom product and said gaseous overhead liquefaction product into a stripper to regenerate the solvent absorbent by forming a solvent bottom product comprising substantially only solvent for use in said absorption column and a stripper top product comprising substantially only carbon dioxide, nitrogen and methane, andrecycling said solvent bottom product back to said absorption column.